Heat sink

ABSTRACT

A heat sink for electronic components has a heat sink contact surface contacting the heat sink with a component to be cooled. At least one SMT fastening surface is disposed at an underside of the heat sink substantially at a right angle relative to the heat sink contact surface. A suction face for an SMT pipette is disposed at the heat sink substantially at a right angle to the heat sink contact surface above the SMT fastening surface. In another version, the heat sink has at least one receptacle slot that extends from an upper side of the heat sink into a wall forming the heat sink contact surface, the receptacle slot serving for the acceptance of a clamp element for clamping the appertaining component tightly against the heat sink contact surface. A suitable clamp element for such a heat sink has a plug-in web adapted in dimensions to the heat sink, a pressure element that presses against the component, and an abutment element that lies against the wall of the heat sink when the heat sink and clamp element are assembled.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention is directed to a heat sink for electronic components having a heat sink contact surface for contacting the heat sink with a component to be cooled.

[0003] 2. Description of the Prior Art

[0004] Metallic heat sinks are employed to dissipate the heat produced by electronic power components such as, for example, transistors or the like as effectively as possible and thus avoid an overheating of the appertaining component. Such heat sinks have a heat sink contact surface in contact with the appertaining component via a thermally conductive connection. The heat sink, due to its good thermal conductivity, its mass and its surface area, absorbs the heat of the component and emits the heat to the environment. A large variety of heat sinks are known in practice, these being respectively adapted to the nature and shape of the electronic components to be cooled, as well as to the purpose, particularly the heat quantity to be eliminated, the available space and the mounting possibilities. When assembling a more complex circuit having many different power components, a corresponding number of different types of heat sinks having different dimensions and shapes therefore must be available. In order to assure a smooth production run in mass production, a higher logistical outlay and more extensive warehousing therefore are necessary for making available the required number of different heat sink types. Equipping of the boards with such heat sinks usually ensues manually. Automatic equipping, for example by means of SMT (surface mount technology) is not possible for the great majority of known heat sinks. Only one SMT-equipable heat sink is known from practice, this having a double T-shaped cross-sectional profile and being placed onto the component to be cooled from above, like a bridge. This heat sink is secured to contact pads on the circuit board with the bottom edges of its T-webs, which form the “bridge supports.” The component to be cooled is located between the T-webs and the area situated between the T-webs contacts the component. In terms of dimensions, these heat sinks must be precisely matched to the dimensions of the component to be cooled. Moreover, it is only possible to employ these heat sinks for cooling SMD (surface mounted device) components that correspondingly mounted on the circuit board with an SMT process. It is not possible to employ these heat sinks for cooling power components that are mounted upright on the circuit board by means of a THT process (through hole technology), i.e. with a plug-through technique. Insofar as different power components are mounted in a circuit with different techniques, different heat sinks must in turn be mounted with the various techniques in successive, separate method steps.

SUMMARY OF THE INVENTION

[0005] An object of the present invention is to provide an alternative heat sink that can be employed as universally as possible and, in particular, can serve for cooling a large variety of components and that can be put in place with different technologies.

[0006] This object is achieved by a heat sink according to the invention having at least one SMT fastening surface that is arranged at an underside of the heat sink substantially at a right angle relative to the heat sink contact surface. With such a “fastening pin”, the heat sink can be secured on a contact pad on the circuit board using standard SMT methods such as auto-gluing processes or pressure gluing processes or within a re-flow soldering process.

[0007] The heat sink also has a suction face for a SMT pipette arranged at the heat sink substantially at a right angle to the heat sink contact surface, above the SMT fastening surface, so that the heat sink can be put in place, for example, with a standard pick-and-place equipping robot. The arrangement of the SMT fastening surface and the suction face each at substantially a right angle relative to the heat sink contact surface makes it possible to automatically mount the heat sink in upright form, i.e. in perpendicular mounting with the heat sink contact surface lying against a standard THT power semiconductor. The heat sink also can be mounted in a horizontal position since the back side of the heat sink contact surface is also very well-suited for grasping the heat sink with an SMT pipette, and the heat sink, thus also can be placed, for example, onto an SMD power semiconductor. Consequently, the heat sink is suited for cooling a multitude of different types of power components that can be mounted on the circuit board in various ways.

[0008] In a second version of the invention, the heat sink has at least one receptacle slot that extends from an upper side of the heat sink into a wall forming the heat sink contact surface, this receptacle serving for the acceptance of a clamp element for clamping the component to be cooled tightly against the heat sink contact surface. This allows a very simple and fast fastening of the component to be cooled to the appertaining heat sink contact surface in that a clamp element is simply pushed into the slot—from above given an upright mounting of the heat sink. The relatively problematic screwing of the component to be cooled to the heat sink is no longer necessary. In particular, this establishes the possibility of utilizing a number of such heat sinks like in a row next to one another, similar to a module, and also reliably secures components of different width to the heat sink row by means of insertion of clamp elements into the mating receptacle slots. As a result, the inventive heat sink can be utilized for components of different widths.

[0009] Preferably the heat sink is fashioned with the features of the first version of the invention as well as the features of the second version of the invention. Such a heat sink is capable of being utilized universally.

[0010] In a preferred embodiment, the (at least one) SMT fastening surfaces is connected to the heat sink via an element that impedes thermal conduction. Such a “heat trap” insures that the SMT fastening surface itself remains relatively cold given a great heating of the heat sink because of a high temperature of the component to be cooled, and the connection between the SMT fastening surfaces and the circuit board therefore does not soften. A firm connection between the heat sink and the circuit board is also assured given higher temperatures of the heat sink. The heat trap fulfills a further function when the SMT heat sink is soldered on the circuit board with only a small fastening pad. The heat demand for the re-flow soldering is then reduced, and the SMT heat sink is securely fastened. Such an element that impedes thermal conduction can be relatively simply realized by the SMT fastening surface being connected to the heat sink only via a thin web.

[0011] In a preferred form that is especially simple to manufacture, the heat sink has a substantially U-shaped profile in a plane lying parallel to the SMT fastening surface. A wall of the U-profile forming the base area of the U also forms the heat sink contact surface, and the two sidewalls of the U-profile forming the U-legs form lateral surfaces that laterally limit the heat sink at the exterior. The two lateral surfaces reside substantially at a right angle relative to the heat sink contact surface. In a preferred embodiment, respective SMT fastening surfaces are arranged at a lower end at each of the two lateral surfaces. It is preferred for each SMT fastening surfaces to project from the lower ends of the two sidewalls into a base area defined by the U-profile, i.e. they do not project laterally beyond the lateral surfaces. When the heat sinks are modularly aligned such that the heat sink contact surfaces form a row, the individual heats sinks can be placed with their lateral surfaces lying directly adjacent to one another. A good heat exchange of the heat sinks with one another thus is also established.

[0012] Preferably the heat sink also is fashioned such that a lower edge of the wall forming the base area of the U terminates downwardly flush with the SMT fastening surfaces 12, as a second heat sink contact surface. This relatively small, second heat sink contact surface that is present in addition to the initially described, first, large heat sink contact surface can be used when the heat sink is to be employed for cooling an SMD component that is cooled via the contact pad of the SMD component, since this second heat sink contact surface can then be placed directly onto the contact pad of the appertaining component. Such a heat sink, consequently, can be employed not only for cooling THT components arranged upright and for horizontal installation on SMD components that are cooled at the upper side, but also can be employed for those SMD components that are cooled downwardly via the contact pad.

[0013] Fundamentally, the suction face of the heat sink can be arranged at an arbitrary position above the SMT fastening surfaces, i.e. laterally thereabove as well. Preferably, however, the suction face of the heat sink is arranged at an upper end of at least one of the two sidewalls, the upper end—by definition—being that end that lies opposite the end of the appertaining sidewall at which the SMT fastening surface is arranged.

[0014] The suction face can extend from the upper end of the appertaining sidewall in the direction of the upper end of the other sidewall, so that the suction face likewise extends into the cross-sectional surface defined by the U-profile—behind the wall forming the heat sink contact surface. In this structure, the suction face is situated directly above the center of gravity of the heat sink, or above the base space defined by the SMT fastening surfaces. The equipping robot therefore can place the heat sink in a relatively uncomplicated way and without any risk of toppling over.

[0015] It is preferred for the suction face to extend at a distance from the wall forming the base area of the U, i.e., there is a spacing between the wall that forms the heat sink contact surface and the suction face. In one configuration of the heat sink in a combined version with an SMT suction face and with a perpendicular receptacle slots for the clamp elements in the wall forming the heat sink contact surface, the receptacle slots are then freely accessible from both sides of the wall, and the clamp elements can be inserted unimpeded into the receptacle slots of the heat sink past the suction face proceeding from the upper side.

[0016] Preferably, the receptacle slots proceed parallel to a lateral surface of the heat sink adjoining the heat sink contact surface. In a heat sink with lateral surfaces arranged substantially at right angles to the heat sink contact surface, it is preferred for a receptacle slot to be arranged in the wall forming the heat sink contact surface at a respectively short distances from the lateral surfaces. Thus, the heat sink has a slot in its heat sink contact surface proceeding parallel to the lateral surface at the right edge as well as at the left edge. This has advantages when the heat sinks are placed next to one another as a module for cooling a larger component, since a component extending essentially over two heat sink widths, for example, can be clamped to one heat sink from the right and to the other heat sink from the left in order to produce a firm contact to the heat sinks.

[0017] In a preferred embodiment, a sub-section of the wall forming the heat sink contact surface, preferably precisely that sub-section between the two receptacle slots, extends upwardly beyond the suction face, or the upper ends of the sidewalls of the heat sink, and thus forms a heat sink extension tongue. Further heat sinks for expanding the cooling capacity can then be secured to this heat sink extension tongue. In particular, it is possible to mount a number of inventive heat sinks in a corresponding grid dimension on a circuit board and to place thereon a standard aggregate heat sink having a number of cooling ribs. By means of a standard spring contacts that are inserted between the ribs of the extension heat sink, the extension heat sink can press against a rib to which inventive heat sinks are secured.

[0018] In order to achieve a good thermal conductivity for applications (RF) wherein zero ohm connections by soldering are required, the heat sink preferably is composed of brass or bronze. In a preferred embodiment, the heat sink is bent from one piece from a sheet metal blank, i.e. no screwing or soldering of individual heat sink parts whatsoever is required for forming the heat sink. This enables a very economical manufacture. The heat sink can be completely tin plated allowing the heat sink to be unproblemmatically connected to the contact pads on the circuit board in a re-flow oven, and allowing heat sinks aligned with one another to be firmly connected to one another and thus form a very stable, large heat sink structure.

[0019] An especially simple and economically manufacturable clamp element for insertion into the aforementioned receptacle slot in one of the versions of the inventive heat sink for clamping a component, has a plug-in web that is adapted in thickness to the width of the receptacle slot and adapted in length to the thickness of the wall forming the heat sink contact surface as well as to the thickness of the component to be clamped. A resilient pressure element that presses against the component in the assembled condition is arranged at one end of the plug-in web. An abutment element that lies against the wall of the heat sink forming the heat sink contact surface in the assembled condition is arranged in the other end region.

[0020] Such a clamp element is likewise relatively simple to manufacture in one piece by appropriate bending from a sheet metal blank. The clamp element preferably is fabricated of bronze or some other resilient material such as, for example, spring steel.

[0021] The two abutment elements preferably each extend at a right angle from the plug-in web as well as at a right angle to the plug-in direction, in directions opposite one another. Preferably the abutment elements extend in parallel planes that are disposed at a distance from one another that is matched to the thickness of the wall of the heat sink forming the heat sink contact surface. Thus, one of the two abutment elements is located at the outside of the appertaining wall in its plugged-in condition and one is arranged at the inside, so that an especially secure holding of the clamp element in the receptacle slot of the heat sink is established.

DESCRIPTION OF THE DRAWINGS

[0022]FIG. 1 is a perspective illustration of the rear of an inventive heat sink.

[0023]FIG. 2 is a perspective illustration of an inventive clamp element.

[0024]FIG. 3 is a plan view of the heat sink according to FIG. 1 with a plugged-in clamp element according to FIG. 2.

[0025]FIG. 4 is a perspective front view of a group of inventive heat sinks that cool components of different widths.

[0026]FIG. 5 is a perspective view of the group of heat sinks according to FIG. 4 as seen from the rear.

[0027]FIG. 6 is a perspective view of a number of heat sinks mounted upright on a circuit board in rows and columns at specific grid dimension.

[0028]FIG. 7 is a perspective illustration of the heat sink arrangement according to FIG. 6 with an plugged-on aggregate heat sink in a first exemplary embodiment.

[0029]FIG. 8 is a perspective illustration of the heat sink arrangement according to FIG. 6 with an plugged-on aggregate heat sink in a second exemplary embodiment.

[0030]FIG. 9 is a perspective view from the rear of a heat sink that cools an SMD power component from below via a circuit board contact pad.

[0031]FIG. 10 is a perspective view of two inventive heat sinks that have their lateral surfaces lying against an SMD power component to be cooled.

[0032]FIG. 11 is a perspective view of an inventive heat sink that is mounted horizontal fashion on the upper side of an SMD component to be cooled.

[0033]FIG. 12 shows an inventive heat sink that, in horizontal fashion, cools a group of four SMD power components.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] In the exemplary embodiment shown in the figures, the heat sink 1, when viewed from above and as clearly shown in FIGS. 1 and 3, has an essentially U-shaped cross-sectional profile.

[0035] The outside of the wall 4 of the U-profile forming the base area of the U is the actual heat sink contact surface 7. At the outside, the sidewalls 5, 6 forming the Ulegs of the U-profile form two lateral surfaces 8, 9 that reside at right angles relative to the heat sink contact surface 7 and that laterally limit the heat sink 1.

[0036] An SMT fastening surface 12 is arranged at each of the lower ends of the sidewalls 5, 6 via a thin web 13 that serves as a heat trap. Each web 13 extends inwardly, i.e. in the direction of the base area defined by the U-profile, so that the SMT fastening surfaces 12 are located within this base area. Given an upright mounting as shown in FIGS. 1, 3 as well as 4 through 10, these SMT fastening surfaces 12 of the heat sink 1 are connected to a circuit board 24 at contact pads 26. The heat trap insures that, given significant heating of the heat sink 1, the SMT fastening surfaces 12 are not heated to the same extent, and the connection between the SMT fastening surfaces 12 and the contact pads 26 of the circuit board 24 are not caused to release. The webs 13 also allow dependable soldering in a reflow soldering process, so that a high heat demand is not needed for pre-heating the heat sink.

[0037] The bottom edge 15 of the wall 4 forming the heat sink contact surface 7, i.e. the base area of the U, terminates downwardly flush with the SMT fastening surfaces 12, so that the bottom edge 15 lies on the circuit board 24 when the heat sink 1 is placed onto a circuit board and is secured on the circuit board at the SMT fastening surfaces 12. This wall 4 projects upwardly beyond the sidewalls 5, 6, formatting a heat sink extension tongue 11. Two receptacle slots 14 proceeding parallel next to the lateral surfaces 8, 9 at a short distance therefrom are located to the right and left next to this upwardly extending tongue 11. The receptacle slots 14 serve for the acceptance of a clamp element 2 according to FIG. 2 that - as shown in FIG. 3 is inserted from above.

[0038] A tab that forms a suction face 10 for an SMT pipette extends at the upper end of the one sidewall 5 in the direction of the other sidewall 6 at a spacing ‘a’ behind the heat sink extension tongue 11, likewise at a right angle relative to the heat sink contact surface, i.e. parallel above the two SMT fastening surfaces 12. This suction face 10 is the pick-and-place fetching surface for the suction pipette of an SMT equipping robot with which the heat sink can be mounted upright on the circuit board 24 in the arrangement shown in FIGS. 1, 3 as well a 4 through 10.

[0039] The distance's' between the suction face 10 and the wall 4 that forms the heat sink contact surface 7 is selected so that the clamp element 2—as shown in FIG. 2—can be plugged unimpeded into the right as well as the left receptacle slot 14 from above.

[0040] The entire heat sink 1 is bent from a single bronze or brass sheet metal blank by the two sidewalls 6 first being bent into U-shape away from the wall 4 of the base area of the U, forming the heat sink contact surface 7, at a right angle. The two SMT fastening surfaces 12—at their webs 13—as well as the tab forming the suction face 10 are bent inwardly into the U-profile. The entire heat sink is subsequently tinplated.

[0041] The appertaining clamp element 2 that serves the purpose of clamping a component 3 a, 3 b to be cooled firmly to the heat sink contact surface 7 given an upright installation is shown in FIG. 2.

[0042] The clamp element 2 is composed of a plug-in web 16 to which a resiliently fashioned pressure tongue 17 is applied at the front side, i.e. that end situated at the outside in front of the heat sink contact surface 7 of the heat sink 1 in the mounted position.

[0043] Abutment elements 20, 21 are situated at the back end of the plug-in web 16. The abutment elements 20, 21—as shown in FIG. 3—engage in front of and behind the wall 4 of the heat sink 1 forming the heat sink contact surface 7 in their assembled condition, and thus producing to a firm seating of the clamp element 2 within the receptacle slot 14 of the heat sink 1.

[0044] The clamp element according to FIG. 2 is bent of one piece from a bronze sheet metal blank. In order to achieve a resilient effect, the pressure tongue 17 is constructed of two sub-sections. The first sub-section 19 arranged at the plug-in web 16 is bent away from the plug-in web 16 so that, in the assembled condition, it points obliquely from the outside in the direction of the mounted component 3 a (see FIG. 3). The second, outer sub-section 18 is in turn bent away from the first subsection 19 at a slight angle, so that it proceeds parallel to the surface of the component 3 a to be cooled and presses flat against the surface of the appertaining component 3 a.

[0045] For forming the abutment elements 21, the plug-in web is doubly slotted proceeding from its back end parallel in the direction in which the plug-in web 16 extends. A middle part situated between the sluts is then bent outwardly at a right angle to the plug-in web 16, namely in a direction opposite the direction in which the pressure tongue 17 extends. Parallel thereto and in an offset plane, the two outer end parts of the plug-in web 16 are each bent at a right angle in the opposite directions, i.e. parallel in the direction in which the pressure tongue 17 extends. The distance between the parallel planes in which the abutment elements 21 and 20 are bent is matched to the thickness of the wall 4 of the heat sink 1 with the receptacle slots 14.

[0046] The heat sink shown in the figures is universally employable for a large variety of SMT and THT power components.

[0047] The heat sink can be automatically placed in any arbitrary direction by means of SMT mounting technology. It is thereby possible to supply the heat sinks 1 to the equipping robot packed in magazines or a frangible series.

[0048] In a preferred embodiment, the weight of the heat sink amounts to no more than 13 g, and the height of the overall heat sink amounts to no more than 20 mm, so that the standard equipping robot requirement are met and, consequently, special equipping robots need not be employed.

[0049] As a result of employing sheet bronze or brass that is tin-plated, the heat sink 1 is highly solderable on all sides, i.e. the heat sink 1 can be soldered in ay orientation to the component, which is important particularly given RF applications. The heat sinks 1 can be arbitrarily joined to one another as modules due to the compact structure that is limited in a rectangular form at the outside. As a result of the all-around tin-plating, moreover, the heat sinks are automatically connected to one another in a re-flow oven in their joined condition so that a stable structure of a heat sink row is produced without requiring an added outlay therefor in the process chain such as, for example, screwing or clamping of the individual heat sink modules to one another.

[0050] Due to the possibility of an SMT mounting in upright fashion with a vertically residing heat sink contact surface 7, THT power components 3 a, 3 b in particular, conventionally that are mounted in upright fashion, also can be cooled. Due to the specific design of the heat sinks 1, an automatic equipping is also possible in this version. First, the boards 24 are equipped with the inventive heat sinks 1 in a work step and are secured on the circuit board 24 in an automatic or pressure gluing process or in a re-flow soldering oven. The THT power components 3 a, 3 b are then put in place following the SMT process, and, finally, are pressed against the inventive heat sinks 1 with the clamp elements 2, as shown in FIGS. 3 through 8.

[0051] There are a number of approaches in order to assure a good heat transmission from the component 3 a, 3 b to the inventive heat sink 1. First, the heat sink contact surface 7 can be equipped with a thermal conduction band that is electrically insulating. Second, the heat sink contact surface can be equipped with an electrically conductive thermal conduction band. For a zero-ohm connection, the heat sink contact surface can simply be soldered well to the component.

[0052]FIGS. 4 through 8 respectively show different mounting modifications for cooling typical THT power semiconductors 3 a, 3 b that are vertically mounted on a board 24. FIGS. 4-8 clearly show the possibility of modularly utilizing the inventive heat sink 1 and, as shown as an example, cooling a relatively narrow power semiconductor 3 a with one heat sink 1 or a broad power semiconductor 3 b with two heat sinks 1. As a result of the slotting at the right and left next to the lateral surfaces 8, 9, the possibility is produced of optionally clamping the power semiconductor 3 a, 3 b from the right, from the left or from both the right and left. To this end, the heat sink 1 should be adapted to the standard grid width dimension of conventional power semiconductors in terms of its width and the spacing dimension between the receptacle slots.

[0053]FIG. 5 shows the same exemplary embodiment again, viewed from the rear. As can be seen in FIG. 5, a second exemplary embodiment of a clamp element 2 is employed. The significant difference compared to the exemplary embodiment according to FIG. 2 is that the abutment elements 22, 23 are located in one plane and press only from behind against the wall 4 of the heat sink 1 forming the heat sink contact surface 7. Compared thereto, the version according to FIG. 2 is somewhat more stable because these clamp elements 2 are held firmly at the position within the receptacle slot 14 even without pressure onto the resilient pressure element 17.

[0054]FIG. 5 also shows (with an arrow) how the inventive heat sinks 1 can be fundamentally supplied to an equipping robot within a channel guide, so that the SMT pipette of the equipping robot can grasp the heat sinks 1 at their SMT suction face 10 and place them onto a circuit board 24.

[0055]FIGS. 6 through 8 show various groupings of rows of the inventive heat sinks 1 opposite and next to one another. The arrangement of the heat sinks 1 preferably ensues in a defined grid dimension, so that simple aggregate heat sinks 28 can be put in place on the heat sink extension tongues 11 of the heat sinks 1, as shown in FIGS. 7 and 8.

[0056]FIG. 7 shows an aggregate heat sink 28 that has ribs 30 only at its underside, so that the upper surface can serve as mounting surface for a system assembly. FIG. 8 shows the grouping with an aggregate heat sink 28 that has cooling ribs 30 at the top and bottom sides. As a result an even greater cooling capacity is available. A firm contact of the inventive heat sink 1 with the expansion-aggregate heat sinks 28 can ensue by employing insertable spring contacts 29 that press the heat sink extension tongues 11 of the appertaining, inventive heat sinks 1 against an adjacent rib 30 of the aggregate heat sink 28. For a force-free mounting, the spring contacts 29 can be pre-stressed with an auxiliary means.

[0057] As shown in FIG. 8, the outside of an aggregate heat sink 28 with ribs 30 on both sides also can have extension clips 31 for connection to other aggregate heat sinks. A number of aggregate heat sinks 28 can be connected to one another by these connection clips 31 by means of clamp connector elements that are already known. With a suitable number of inventive heat sinks 1 arranged upright, a large surface of individual aggregate heat sinks 28 can be formed, these being placed against one another in the fashion of parquetry and cooling the heat sinks 1 situated thereunder in the matching grid dimension with the power components 3 a, 3 b arranged thereon in common.

[0058]FIGS. 9 through 12 show various exemplary embodiments of how typical SMD power components 3 c can be cooled with the inventive heat sinks 1.

[0059] As shown in FIGS. 9-12, such an SMD component 3 c is usually electrically connected to the circuit via contact pads 25, 27 and is simultaneously firmly connected to the circuit board 24 by being soldered to these contact pads 25, 27. There are usually two different approaches for cooling such SMD components 3 c.

[0060] The one approach is to cool the component 3 c from below, i.e. indirectly via the contact pad 25. The component 3 c radiates the heat via the contact pad 24 under the component 3 c. The heat sinks 1 absorb the heat via the thermal pad link 25, 26 - via the wall 4 forming the heat sink contact surface 7, if possible - and carry the heat away.

[0061]FIG. 9 shows a first exemplary embodiment of this first approach. Here, the inventive heat sink 1—standing uptight—is secured such to the contact pads 26 on the circuit board 24 that the bottom edge 15 of the wall 4 forming the (principal) heat sink contact surface simultaneously lies on the contact pad of the component 3 c and thus serves as heat sink contact surface for this applied purpose.

[0062] In a second exemplary embodiment according to FIG. 10 for this first approach, the cooling ensues by means of two heat sinks 1 that absorb heat with their contact pads 26 and—insofar as possible—with the walls 4 forming the heat sink contact surfaces 7 and eliminate it.

[0063] The equipping can ensue in the usual way with an SMT equipping robot given both the exemplary embodiment according to FIG. 9 and the exemplary embodiment according to FIG. 10. An expansion of the cooling capacity with an aggregate heat sink as shown in FIGS. 7 and 8 is again possible here.

[0064] In a second approach according to FIGS. 11 and 12, the heat sink 1 has its heat sink contact surface 7 is placed horizontally from above onto the component 3 c to be cooled. For example, the heat sink 1 can thereby be glued with thermally conductive adhesive onto the component 3 c to be cooled.

[0065] As shown in FIG. 12, it is also possible for a heat sink 1 to be placed onto a group of SMD power semiconductors 3 c suitably positioned against one another and therefore cools this group in common.

[0066] Equipping with an SMT equipping robot is also fundamentally possible given this horizontal structure according to FIGS. 11 and 12, since the SMT pipette, of course, can hold at the inside of the wall 4 of the heat sink 1 that forms the heat sink contact surface 7. The only thing required for this purpose is that the heat sinks 1 be supplied to the equipping robot in horizontal form, for example in a palette magazine.

[0067] The exemplary embodiments show the especially large variability of the inventive heat sink in view of the range of employment. Particularly due to the possibility of modularly employing the heat sink, nearly unlimited possibilities are available for utilizing the heat sink to cool the most diverse components, with an automatic equipping being possible in nearly every version. As a result of the possibility of clamping, the outlay for securing a good contact of the heat sink 1 to the component 3 a, 3 b to be cooled is extraordinarily low. Moreover, the heat sink 1 itself as well as the clamp element 2 can be bent from simple sheet metal blanks in an especially economical way.

[0068] Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventors to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of their contribution to the art. 

We claim as our invention:
 1. A heat sink for cooling an electronic component, comprising: a heat sink base in thermal communication with a heat sink contact surface, adapted for thermal contact with an electronic component to be cooled; at least one SMT fastening surface disposed at an underside of said heat sink base substantially at a right angle relative to said heat sink contact surface; and a suction face adapted to interact with an SMT pipette, said suction face being connected to said heat sink base substantially at a right angle to said heat sink contact surface and above said SMT fastening surface.
 2. A heat sink as claimed in claim 1 further comprising an element impeding thermal conduction connecting said at least one SMT fastening surface to said heat sink base.
 3. A heat sink as claimed in claim 2 wherein said element comprises a thin web.
 4. A heat sink as claimed in claim 1 wherein said heat sink base and said heat sink contact surface are formed by a wall, said heat sink further comprising two sidewalls connected to said wall and forming a U-profile in a plane parallel to said SMT fastening device.
 5. A heat sink as claimed in claim 4 wherein each of said sidewalls has a lower end, and comprising two SMT fastening surfaces, one of said SMT fastening surfaces being disposed at the lower end of each of said sidewalls.
 6. A heat sink as claimed in claim 5 wherein, proceeding from said lower ends of said sidewalls, the SMT fastening surfaces project into a base area defined by said U-profile.
 7. A heat sink as claimed in claim 4 wherein said heat sink contact surface is a first heat sink contact surface, and wherein said wall has a bottom edge at said heat sink base terminating flush with said at least one SMT fastening surface, said bottom edge forming a second heat sink contact surface.
 8. A heat sink as claimed in claim 4 wherein each of said sidewalls has an upper end, and wherein said suction face is disposed at the upper end of one of said sidewalls.
 9. A heat sink as claimed in claim 8 wherein said suction face proceeds from said upper end of said one of said sidewalls toward the upper end of the other of said sidewalls.
 10. A heat sink as claimed in claim 8 wherein said suction face is disposed at a distance from said wall.
 11. A heat sink as claimed in claim 8 further comprising an extension tongue proceeding upwardly from said heat sink contact surface as an extension of said wall beyond said upper ends of said sidewalls and said suction face.
 12. A heat sink as claimed in claim 1 wherein said heat sink base, said heat sink contact surface, said at least one SMT fastening surface and said suction face are all comprised of a material selected from the group consisting of brass, bronze and copper.
 13. A heat sink as claimed in claim 1 wherein said heat sink base, said heat sink contact surface, said at least one SMT fastening surface and said suction face are all bent from a one-piece sheet metal blank.
 14. A heat sink as claimed in claim 1 wherein said heat sink base, said heat sink contact surface, said at least one SMT fastening surface and said suction face are all tin plated.
 15. A heat sink for cooling an electronic component, said heat sink comprising: a heat sink base; a heat sink contact surface adapted for thermal contact with an electronic component to be cooled, said heat sink contact surface and said heat sink base forming a wall having an upper side, said wall having a slot therein proceeding into said wall from said upper side; and a clamp element received in said slot and disposed to clamp a component to be cooled between said clamp element and said heat sink contact surface.
 16. A heat sink as claimed in claim 15 comprising a lateral surface connected to said wall, said slot being disposed parallel to said lateral surface.
 17. A heat sink as claimed in claim 15 further comprising at least one further slot disposed parallel to said slot.
 18. A heat sink as claimed in claim 15 comprising two lateral surfaces connected to said wall and each disposed substantially at a right angle relative to said wall, and wherein said slot is a first slot and said heat sink further comprising a second slot in said wall, said first slot being disposed next to one of said lateral surfaces and said second slot being disposed next to the other of said lateral surfaces.
 19. A heat sink as claimed in claim 18 wherein said wall and said lateral surfaces and said clamp element are all composed of a material selected from the group consisting of brass, bronze and copper.
 20. A heat sink as claimed in claim 18 wherein said wall and said lateral surfaces and said clamp element are all tin plated.
 21. A heat sink as claimed in claim 18 wherein said wall and said lateral surfaces are bent from a one-piece sheet metal blank.
 22. A heat sink as claimed in claim 12 wherein said slot has a width and wherein said wall has a thickness, and wherein said clamp element comprises: a plug-in web received in said slot and having a thickness corresponding to the width of said slot and a length corresponding to the thickness of the wall and a dimension of an electronic component adapted to be clamped between said clamp element and said heat sink contact surface; at least one pressure element connected to said plug-in web and adapted to press against an electronic component between said clamp element and said heat sink contact surface; and at least one abutment element connected to said plug-in web disposed against said wall, said pressure element and said abutment element being disposed at opposite ends of said plug-in web.
 23. A heat sink as claimed in claim 22 wherein said clamp element comprises two abutment surfaces respectively proceeding at right angles from said plug-in web in directions opposite from each other, said plug-in web having a plug-in direction associated therewith along which said plug-in web is plugged into said slot, and said two abutment elements being disposed at a right angle relative to said plug-in direction.
 24. A heat sink as claimed in claim 22 wherein said clamp element comprises two abutment elements disposed in parallel planes spaced from each other and being matched to said thickness of said wall.
 25. A heat sink for cooling an electronic component, comprising: a heat sink base; a heat sink contact surface adapted for thermal contact with an electronic component to be cooled, said heat sink contact surface and said heat sink base forming a wall having an upper side, said wall having a slot therein proceeding into said wall from said upper side; at least one SMT fastening surface disposed at an underside of said heat sink base substantially at a right angle relative to said heat sink contact surface; a suction face adapted to interact with an SMT pipette, said suction face being connected to said heat sink base substantially at a right angle to said heat sink contact surface and above said SMT fastening surface; and a clamp element received in said slot and disposed to clamp a component to be cooled between said clamp element and said heat sink contact surface.
 26. An electronic circuit comprising: a circuit board; an electronic component mounted on said circuit board; and a heat sink comprising a heat sink base in thermal communication with a heat sink contact surface, in thermal contact with said electronic component to cool said electronic component, at least one SMT fastening surface disposed at an underside of said heat sink base substantially at a right angle relative to said heat sink contact surface; and a suction face adapted to interact with an SMT pipette, said suction face being connected to said heat sink base substantially at a right angle to said heat sink contact surface and above said SMT fastening surface.
 27. An electronic circuit as claimed in claim 26 wherein said heat sink is mounted on said circuit board in an upright position with said heat sink contact surface disposed substantially at a right angle to said circuit board.
 28. An electronic circuit as claimed in claim 26 wherein said electronic component is disposed in direct contact with said heat sink contact surface.
 29. An electronic circuit as claimed in claim 26 wherein said heat sink contact surface is a first heat sink contact surface, and wherein said electronic circuit comprises a contact pad on said circuit board for said electronic component, and wherein said heat sink base has a bottom edge disposed on said contact pad and forming a second heat sink contact surface for said component.
 30. An electronic circuit as claimed in claim 26 wherein said heat sink is disposed horizontally on said electronic component.
 31. An electronic circuit as claimed in claim 26 comprising a plurality of electronic components, and wherein said heat sink is a first heat sink and further comprises lateral surfaces connected to and disposed at opposite sides of, said wall, and wherein said electronic circuit comprises a plurality of heat sinks identical to said first heat sink respectively in thermal contact with said plurality of electronic components, said plurality of heat sinks being disposed side-by-side with the respective lateral surfaces of adjacent heat sinks facing each other, with the respective heat sink contact surfaces of said plurality of heat sinks being aligned in a row.
 32. An electronic circuit as claimed in claim 26 further comprising an extension heat sink, separate from said heat sink, in thermal contact with said heat sink.
 33. An electronic circuit as claimed in claim 32 wherein said heat sink has an extension tongue connected to and disposed above said heat sink contact surface, said heat sink and said extension heat sink being in thermal contact via said extension tongue.
 34. An electronic circuit comprising: a circuit board; an electronic component mounted on said circuit board; and a heat sink comprising a heat sink base, a heat sink contact surface in thermal contact with said electronic component to cool said electronic component, said heat sink contact surface and said heat sink base forming a wall having an upper side, said wall having a slot therein proceeding into said wall from said upper side, and a clamp element received in said slot and disposed to clamp a component to be cooled between said clamp element and said heat sink contact surface.
 35. An electronic circuit as claimed in claim 34 wherein said heat sink is mounted on said circuit board in an upright position with said heat sink contact surface disposed substantially at a right angle to said circuit board.
 36. An electronic circuit as claimed in claim 34 wherein said electronic component is disposed in direct contact with said heat sink contact surface.
 37. An electronic circuit as claimed in claim 34 wherein said heat sink contact surface is a first heat sink contact surface, and wherein said electronic circuit comprises a contact pad on said circuit board for said electronic component, and wherein said heat sink base has a bottom edge disposed on said contact pad and forming a second heat sink contact surface for said component.
 38. An electronic circuit as claimed in claim 34 wherein said heat sink is disposed horizontally on said electronic component.
 39. An electronic circuit as claimed in claim 34 comprising a plurality of electronic components, and wherein said heat sink is a first heat sink and further comprises lateral surfaces connected to and disposed at opposite sides of, said wall, and wherein said electronic circuit comprises a plurality of heat sinks identical to said first heat sink respectively in thermal contact with said plurality of electronic components, said plurality of heat sinks being disposed side-by-side with the respective lateral surfaces of adjacent heat sinks facing each other, with the respective heat sink contact surfaces of said plurality of heat sinks being aligned in a row.
 40. An electronic circuit as claimed in claim 34 further comprising an extension heat sink, separate from said heat sink, in thermal contact with said heat sink.
 41. An electronic circuit as claimed in claim 40 wherein said heat sink has an extension tongue connected to and disposed above said heat sink contact surface, said heat sink and said extension heat sink being in thermal contact via said extension tongue. 